Beryllium-10 Explained

Num Neutrons:	6
Num Protons:	4
Mass Number:	10
Abundance:	trace
Symbol:	Be
Decay Product:	^10B (bold for stable nuclides)
Spin:	0+
Decay Mode1:	β^−
Decay Energy1:	0.5560^[1] ^[2]

Beryllium-10 (¹⁰Be) is a radioactive isotope of beryllium. It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen.^{[3] [4] [5]} Beryllium-10 has a half-life of 1.39 × 10⁶ years,^{[6] [7]} and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV. It decays through the reaction ¹⁰Be→¹⁰B + e⁻. Light elements in the atmosphere react with high energy galactic cosmic ray particles. The spallation of the reaction products is the source of ¹⁰Be (t, u particles like n or p):

¹⁴N(t,5u)¹⁰Be; Example: ¹⁴N(n,p α)¹⁰Be

¹⁶O(t,7u)¹⁰Be

Because beryllium tends to exist in solutions below about pH 5.5 (and rainwater above many industrialized areas can have a pH less than 5), it will dissolve and be transported to the Earth's surface via rainwater. As the precipitation quickly becomes more alkaline, beryllium drops out of solution. Cosmogenic ¹⁰Be thereby accumulates at the soil surface, where its relatively long half-life (1.387 million years) permits a long residence time before decaying to ¹⁰B.

¹⁰Be and its daughter product have been used to examine soil erosion, soil formation from regolith, the development of lateritic soils and the age of ice cores.^[8] It is also formed in nuclear explosions by a reaction of fast neutrons with ¹³C in the carbon dioxide in air, and is one of the historical indicators of past activity at nuclear test sites. ¹⁰Be decay is a significant isotope used as a proxy data measure for cosmogenic nuclides to characterize solar and extra-solar attributes of the past from terrestrial samples.^[9]

The rate of production of beryllium-10 depends on the activity of the sun. When solar activity is low (low numbers of sunspots and low solar wind), the barrier against cosmic rays that exists beyond the termination shock is weakened (see Cosmic ray#Cosmic-ray flux). This means more beryllium-10 is produced, and it can be detected millennia later. Beryllium-10 can thus serve as a marker of Miyake events, such as the 774-775 carbon-14 spike. There can be an effect on climate^[10] (see Homeric Minimum).

See also

• Surface exposure dating

Notes and References

1. Web site: Decay Radiation: ¹⁰Be . . . 2013-10-16 .
2. 10.1016/j.nuclphysa.2004.09.059 . Energy levels of light nuclei . 2004 . Tilley . D.R. . Kelley . J.H. . Godwin . J.L. . Millener . D.J. . Purcell . J.E. . Sheu . C.G. . Weller . H.R. . Nuclear Physics A . 745 . 3–4 . 155–362 .
3. G.A. Kovaltsov. I.G. Usoskin. Earth Planet. Sci. Lett.. 291. 1–4. 2010. 182–199. A new 3D numerical model of cosmogenic nuclide ¹⁰Be production in the atmosphere. 10.1016/j.epsl.2010.01.011. 2010E&PSL.291..182K.
4. Book: J. Beer. K. McCracken. R. von Steiger. 2012. Physics of Earth and Space Environments, Springer, Berlin . Cosmogenic radionuclides: theory and applications in the terrestrial and space environments. 26. 10.1007/978-3-642-14651-0. Physics of Earth and Space Environments. 978-3-642-14650-3. 55739885.
5. S.V. Poluianov. G.A. Kovaltsov. A.L. Mishev. I.G. Usoskin. J. Geophys. Res. Atmos.. 121. 13. 2016. 8125–8136. Production of cosmogenic isotopes ⁷Be, ¹⁰Be, ¹⁴C, ²²Na, and ³⁶Cl in the atmosphere: Altitudinal profiles of yield functions. 10.1002/2016JD025034. 1606.05899. 2016JGRD..121.8125P. 119301845.
6. G. Korschinek. A. Bergmaier. T. Faestermann. U. C. Gerstmann. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 268. 2. 2010. 187–191. A new value for the half-life of ¹⁰Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting. 10.1016/j.nimb.2009.09.020. 2010NIMPB.268..187K.
7. J. Chmeleff. F. von Blanckenburg. K. Kossert. D. Jakob. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 268. 2. 2010. 192–199. Determination of the ¹⁰Be half-life by multicollector ICP-MS and liquid scintillation counting. 10.1016/j.nimb.2009.09.012. 2010NIMPB.268..192C.
8. Balco. Greg. Shuster. David L.. 2009. ²⁶Al-¹⁰Be–²¹Ne burial dating. Earth and Planetary Science Letters. 286. 3–4. 570–575. 10.1016/j.epsl.2009.07.025. 2009E&PSL.286..570B. 2012-12-10. 2015-09-23. https://web.archive.org/web/20150923184215/http://www.bgc.org/shuster/BalcoShuster(2009b)_Al_Be_Ne_burial_dating.pdf. dead.
9. Paleari . Chiara I. . F. Mekhaldi . F. Adolphi . M. Christl . C. Vockenhuber . P. Gautschi . J. Beer . N. Brehm . T. Erhardt . H.-A. Synal . L. Wacker . F. Wilhelms . R. Muscheler . Cosmogenic radionuclides reveal an extreme solar particle storm near a solar minimum 9125 years BP . Nat. Commun. . 13 . 214 . 2022 . 214 . 10.1038/s41467-021-27891-4 . 35017519 . 8752676 . 2022NatCo..13..214P . free .
10. Philip Ball . Flickering sun switched climate . Nature . Dec 19, 2001 . 10.1038/news011220-9.